Sandoz CV 205-502 is a new dopamine agonist which is known to lower prolactin levels. It also is longer-acting and may have less central emetic activity compared to bromocryptine. The protocol is a multicenter study to investigate the efficacy of CV 205-502 to suppress prolactin levels and reduce tumour size in patients with microprolactinomas (i.e., prolactin levels greater than 100ng/ml and tumours greater than 1cm in size).